In the spring of 1850 Agassiz married Elizabeth Cabot Cary, daughter of Thomas Graves Cary, of Boston. This marriage confirmed his resolve to remain, at least for the present, in the United States. It connected him by the closest ties with a large family circle, of which he was henceforth a beloved and honored member, and made him the brother-in-law of one of his most intimate friends in Cambridge, Professor C.C. Felton. Thus secure of favorable conditions for the care and education of his children, he called them to this country. His son (then a lad of fifteen years of age) had joined him the previous summer. His daughters, younger by several years than their brother, arrived the following autumn, and home built itself up again around him. The various foreign members of his household had already scattered. One or two had returned to Europe, others had settled here in permanent homes of their own. Among the latter were Professor Guyot and M. de Pourtales, who remained, both as scientific colleagues and personal friends, very near and dear to him all his life. "Papa Christinat" had also withdrawn. While Agassiz was absent on a lecturing tour, the kind old man, knowing well the opposition he should meet, and wishing to save both himself and his friend the pain of parting, stole away without warning and went to New Orleans, where he had obtained a place as pastor. This was a great disappointment to Agassiz, who had urged him to make his home with him, a plan in which his wife and children cordially concurred, but which did not approve itself to the judgment of his old friend. M. Christinat afterward returned to Switzerland, where he ended his days. He wrote constantly until his death, and was always kept advised of everything that passed in the family at Cambridge. Of the old household, Mr. Burkhardt alone remained a permanent member of the new one. CHAPTER 16. 1850-1852: AGE 43-45. Proposition from Dr. Bache. Exploration of Florida Reefs. Letter to Humboldt concerning Work in America. Appointment to Professorship of Medical College in Charleston, S.C. Life at the South. Views concerning Races of Men. Prix Cuvier. THE following letter from the Superintendent of the Coast Survey determined for Agassiz the chief events of the winter of 1851. FROM ALEXANDER DALLAS BACHE. WEBB'S HILL, October 30, 1850. MY DEAR FRIEND,